<?
    header("Content-type:text/xml");
    // header("Content-type:text/xml");
    $str = <<<AAA
    <?xml version = "1.0" encoding = "utf-8" ?>
    
        <books>
            <nodejs>
                <name>nodejs从入门到放弃</name>
                <price>￥50</price>
            </nodejs>
            <reactjs>
                <name>reactjs从入门到放弃</name>
                <price>￥60</price>
            </reactjs>
        </books>
    AAA;
    echo $str ; 
?>